Mitch's post (excerpted below), together with his earlier response on this
topical thread, point to the key reason, IMO, why materialism is essential
to any realistic worldview. I would put it this way:

No software without hardware.

I think many people, especially intellectuals, can be seduced by the meme of
idealism. The idealist (or Platonic) concept that information (or Forms)
precede material manifestation is very attractive to people whose lives
revolve around theorizing, computation, and programming. Many philosophers,
mathematicians and logicians succumb to this point of view (Raymond Smullyan
and Saul Kripke, for instance). Some physicists do, too (e.g., Frank
Tipler).

Life, the universe and everything may be implementable on a variety of
different material platforms under a range of different physical parameters.
But they cannot be implemented without SOME material platform. The lowest
level of implementation of any computational system (Turing-Church
finite-state machine) must be material. At the bottom of any chain of
systems emulating other systems is a fundamental physical platform that is
independent of anything else.

So, to borrow and modify an old analogy: It's turtles **almost** all the way
down, but at bottom it's physics.

Regards,
Michael LaTorra

> -----Original Message-----
> From: owner-sl4@sl4.org [mailto:owner-sl4@sl4.org]On Behalf Of Mitchell
> Porter
...
>
> Suppose fundamental physics turned out to be described by the
> Game of Life. What would that mean? It would mean that the universe
> was made of two-state entities which are causally coupled to each
> other in a certain way. If someone wanted to say that such a
> universe was "made of finite-state machines", each running the
> basic state-transition law as their "program" - I would find that
> a lot more reasonable. But the idea that the universe is made of
> software that has no hardware... it's like Pythagoras, "all is
> number". His heart was in the right place, but it would have been
> more accurate to say "All is particle" or "All is field", with
> the numbers
> playing a supporting role. I think our contemporary
> attempts to make a fundamental information ontology are going
> to require a similar compromise with materialism before they get
> off the ground.